A liquid crystal display apparatus and the like have been typically used as a light-emitting apparatus used for a display. In recent years, as another light-emitting apparatus, an organic electroluminescent light-emitting apparatus using an organic electroluminescent device (hereinafter, occasionally abbreviated as an “organic EL device”) also has been put into practical use. In the organic EL device, a light-emitting unit including a light-emitting layer is provided between an anode and a cathode and light emission is provided by exciton energy generated by recombination of holes and electrons injected to the emitting layer.
A light-emitting apparatus used for a color display is mainly exemplified by a three-color light-emitting apparatus and a color-filter light-emitting apparatus.
In the three-color light-emitting apparatus, a color display is obtained by forming devices capable of respectively emitting light in three primary colors of red (R), green (G) and blue (B) and controlling a luminous intensity of each of the three colors. However, the three-color light-emitting apparatus requires a high-definition coating using a metal mask when coating, evaporation or the like is performed in order to form light-emitting layers that emit the respective colors of RGB.
On the other hand, in the color-filter light-emitting apparatus, a white light-emitting device and a color filter are used. White light is converted into three colors of RGB by passing through the color filter. Since the color-filter light-emitting apparatus does not require a high-definition coating, the color-filter light-emitting apparatus can be manufactured more easily than the three-color light-emitting apparatus.
The white light-emitting device exemplarily includes: an anode; a cathode; and a single light-emitting unit interposed between the anode and the cathode, in which two light-emitting layers are laminated to each other in the light-emitting unit. The two light-emitting layers simultaneously emit light, thereby providing white light emission as the entire light-emitting unit.
Another arrangement of the white light-emitting device is a so-called tandem arrangement including an anode, a cathode, a plurality of light-emitting units interposed between the anode and the cathode, in which the light-emitting units are laminated to each other through an intermediate layer (e.g., an intermediate electrode) therebetween.
Patent Literature 1 discloses a display apparatus including the tandem organic EL device in combination with a color filter.
The organic electroluminescence device included in the display apparatus disclosed in Patent Literature 1 is provided by a white light-emitting device that includes: an anode; a cathode; a first light-emitting unit having a red light-emitting layer and a green light-emitting layer; a second light-emitting unit having a blue light-emitting layer; and a connection layer (intermediate layer) interposed between the first and second light-emitting units, the first and second light-emitting units and the intermediate layer being provided between the anode and the cathode. In the display apparatus disclosed in Patent Literature 1, the white light-emitting devices are disposed to the respective RGB filters. When each of the white light-emitting devices emits white light, the white light passes through the color filters to convert the color of the light.